In drilling, completing and operating subsea oil and gas wells a sealing connection must be established between two hubs. In general, this may be accomplished by use of a connector that contains a locking means for clamping the two hubs together so as to establish the seal between the two hubs. The structures and configurations of the hubs and the connector, as well as the mechanisms used to establish the sealing connection between such hubs is vast and varied. As one example, in the oil and gas industry, subsea wells normally have a large tubular wellhead positioned at the sea floor. A component such as a Christmas tree or a blowout preventer is that is coupled to the wellhead (or another component) via the connection between two such hubs. Typically, a wellhead connector is attached to a first component that contains a first hub that is adapted to be coupled to the wellhead (a second hub) by the use of a hydraulically actuated connector. Typically, the sealing connection between the two hubs is established by actuating one or more hydraulic cylinders to force “dogs” into engagement with a profile (e.g., grooves) formed in the outer surface of the wellhead. Another example from the oil and gas industry is subsea flow lines wherein connections must be made between two tubular shaped flow lines that carry hydrocarbon fluids and gases. The hubs may be part of any of a variety of different types of equipment or structures, e.g., Christmas trees, a subsea well head, a subsea jumper, a manifold, a pipeline, a flow line, a Pipeline End Module (PLEM), a Pipeline End Termination (PLET), etc.
In general, a first component, e.g., a manifold, is located on the sea floor. The manifold contains a first hub that is adapted to be coupled to a second hub on second piece of equipment, such as a subsea jumper that will be lowered toward the subsea floor using a crane that is positioned on surface vessel. In general, alignment means are provide to approximately align the two hubs as the second component nears the first component on the sea floor. One example of such alignment means includes an upstanding rod positioned proximate the first hub and a downward facing funnel shaped device that is attached to the second hub. As the second piece of equipment nears the first piece of equipment, the funnel engages the upstanding rod to approximately align the two hubs relative to one another. While all of this positioning and alignment is occurring, the vessel at the surface is subjected to the wave conditions at the surface of the body of water. Thus, the second piece of equipment, even after alignment with the funnel device, may still heave upward and downward as the vessel at the surface experiences the surface wave conditions. In practice, once the rod and funnel are properly engaged, and the two hubs are separated by a small distance, e.g., 5-20 inches (12.7-50.80 cm), the second component may simply be dropped onto the first component, i.e., the second hub is dropped on the first hub.
This dropping is problematic for several reasons. First, there is the risk of damaging the sealing surfaces on the two hubs if there is any misalignment between the two hubs. Second, the hubs are normally sealed together using a metal seal ring that is typically positioned in the second hub of the second component as the second component is lowered toward the see floor. If the second component is simply dropped on the first component, the metal seal ring may be damaged thereby preventing the establishment of a proper seal between the two hubs.
The present application is directed to a unique passively locking connector with a delayed release-latching mechanism that may eliminate or at least minimize some of the problems noted above.